Absolute frequency measurement of the ${}^{176}$Lu${}^{+}{(}^3{\mathrm{D}}_1)$ standard against the NRC-FCs2 fountain with $2.6\times 10^{-16}$ uncertainty

K. J. Arnold, Bin Jian, Zhao Zhang +6

We report an improved absolute frequency measurement of the ${}^{176}$Lu${}^{+}{(}^3{\mathrm{D}}_1)$ optical frequency standard, evaluated via a remote link to the NRC-FCs2 caesium fount…